[unreadable] The primary goal of this project is to develop a prototype of a silicon-based structure, the "neurochip" which will support the growth and development of cultured neural networks and will greatly enhance the ability of researchers to study them. The structure will be an array of 61 "wells" into which dissociated neurons can be placed, and which will hold each of them in proximity to an extracellular electrode. The wells will allow process outgrowth of axons and dendrites and be closely spaced so as to support synaptic connectivity of the neurons to form a network. The prototype can be scaled up to larger networks, and the fabrication method will be compatible with on-chip CMOS electronics for on-chip processing, control, and wireless communication. [unreadable] [unreadable] The electrodes will provide the capability to stimulate and record from any chosen neurons of the network non-destructively, supporting studies of the network connectivity over time; of patterns of spontaneous activity;, and of activity-dependent effects resulting from stimulation. A second goal of the project is to utilize neurochips to perform an initial series of experiments which will reveal the development of connections, the effects of stimulation on remodeling the network and the creation of "learned" responses. These will provide unique knowledge of network behavior, in detail, beyond what is now possible with available techniques in vivo or in vitro. [unreadable] [unreadable] In addition, neurochip networks have the potential to reveal pharmacological effects relevant to drug design and deveIopment, and also to exhibit the effects on nervous system function of genetic defects. [unreadable] [unreadable]